Oh come on, folks! It's just a more or less generic blessing and indication of goodwill and more of a habit. I doubt very much if everybody who says "God Bless You" means it as an insult to everyone who doesn't believe as they do.

I'm a general heathen who thinks most "Pagans" are way too preachy for my tastes anyway... damn near as bad as a lot of born-again Christians in their way.

And for the record, if you want to get pedantic about it, the whole tradition comes from an old superstition that your soul was in particular jeopardy of being stolen or lost during the instant of a sneeze. Ectoplasmic snot? Very Christian, non?